Very sad to hear about this.
A little tip, when in a circuit at a CTAF, talk to the other traffic and let them know the sequence, ie take control. If you join downwind and there is someone late downwind, i will say, "i will make number 2 to you", or if it was reversed, i would say "i will make number 1 to you".
Always helps to be pro-active than re-active.